Process for controlling nematodes

ABSTRACT

Process for controlling nematodes by treating nematode infested soil with a toxic quantity of 4-aminobiphenyl or a derivative thereof which is capable of being hydrolyzed to 4-aminobiphenyl.

United States Patent 1151 3,674,878

Degginger et al. July 4, 1972 [54] PROCESS FOR CONTROLLING [56] References Cited NEMATODES 72 1 Ed d R OTHER PUBLICATIONS t D C t St t l 1 men jfi fi fiTfig g Stahletal.,Chem. Abst. v01. 39 pages 3111-3112, 1944.

Md. I Primary Examiner-Albert T. Meyers [73] Ass1gnee: Allied Chemical Corporation, New York, Assistant E i -All J, Robinson Atl0rneyArthur J. Plantamura [22] Filed: May 4,1970

[57] ABSTRACT [2]] Appl. N0.: 34,559

Process for controllmg nematodes by treating nematode 1nfested soil with a toxic quantity of 4-aminobiphenyl or a derivative thereof is capable of being hydrolyzed to 4.

[51] Int. Cl. ..A6ln 9/20 aminobiphenyl.

[58] Field oiSearch ..424/330 1 Claim, No Drawings PROCESS FOR CONTROLLING NEMATODFS BACKGROUND OF THE INVENTION DETAILED DESCRIPTION It is an object of the present inventionto provide a method of controlling nematodes by treating nematode-infested soil with a toxic quantity of a nematocide which is capable of thoroughly permeating the soil and incapacitating the nematode population therein.

As used in this specification and in the appended claims, the term controlling nematodes means incapacitating a sufficient number of nematodes, for example by killing or'paralyzing them, so as to substantially reduce the injurious effect of the nematodes on plant appearance and growth. Thus, the nematocide does not necessarily have to kill all nematodes present in the soil in order to be effective. Generally incapacitation of at least 50 percent of the nematodes is clearly advantageous. However, incapacitation of at least about 70 percent is preferred, with incapacitation of at least about 90 percent being most preferred.

It has now been discovered that control of nematodes may be effected by treating nematode-infested soil with a toxic quantity of a nematocide selected from the group consisting of a 4-aminobiphenyl, having the formula and derivatives thereof which are capable of being hydrolyzed, preferably in the soil, to 4-aminobiphenyl.

Suitable derivatives of 4-aminobiphenyl, i.e. those derivatives which are capable of being hydrolyzed back to 4- aminobiphenyl, include 4-isocyanato biphenyl, having the formula 4-isothiocyanato biphenyl, having the formula and wherein R contains from one to eight carbon atoms and is selected from the group consisting of alkyl, alkenyl, aryl, alkaryl, uralkyl and cycloalkyl. Preferably R is an alkyl radical of one to three carbon atoms. I

The 4-biphenyl carbamates, '4-biphenyl thiocarbamates, and4-biphenyl dithiocarbamates used in this invention have the respective formulas wherein R is defined as above.

Illustrative of suitable R groups are and and the like.

The 4-aminobiphenyl may be prepared by conventional methods. Generally it is prepared by first nitrating biphenyl and then reducing the resulting nitro compound to the corresponding amine. The biphenyl compounds capable of being hydrolyzed to 4-arninobiphenyl may be prepared by any conventional means known in the art. For example, 4-biphenyl isothiocyanate may be prepared by reacting 4-aminobiphenyl with thiophosgene, and 4-biphenyl isocyanate may be prepared by reacting 4-aminobiphenyl with phosgene.

The nematocides of the present invention may be introduced into the soil as is or in a variety of nematocidal compositions. The nature of these compositions will depend primarily upon the particular composition contemplated. The compositions may be applied to the nematode-infested soil in any conventional manner as by spraying, drenching or dusting. The term soil" as used herein is intended to include any medium capable of supporting the growth of plants. It is therefore intended to include, in addition to soil, humus, manure, compost, sand and artificial plant growth media, including hydroponic media.

In a preferred embodiment of the invention, the nematocides are distributed in the soil by introduction in water such as that employed to irrigate the soil. In this procedure the amount of water may be varied in accordance with the moisture equivalent of soil in order to obtain the desired depth of distribution of the toxic compound.

The nematocides described above may also be formulated as dust or granular compositions containing carrier or fillers such as talc, sand, fuller's earth, chalk, gypsum, etc., including active ingredients such as fertilizers, insecticides and fungicides. Generally, the nematocides may be used for controlling nematodes in either pre-emergence or post-emergence treatments without substantially affecting crops planted or growing in the soil.

The 4-aminobiphenyl and the suitable derivatives thereof are effective as nematocides when distributed in the infested soil at a dosage which is generally greater than about 10 pounds per acre and preferably between about 30 and about EXAMPLE 1 The nematocidal activities of 4-aminobiphenyl and 4- isothiocyanato biphenyl were determined by preparing various strength water solutions of the two compounds and then adding one drop of a nematode culture to each solution. After 3 days, the results were observed and recorded as estimated percentage kill of nematodes. The results are given in the following table for three different concentrations of the compounds in water:

TABLE 1 Compound Kill after 3 days 125 ppm 62.5 ppm 31.2 ppm 4-arninobiphenyl 100 100 100 4-isothiocyanato biphenyl 100 100 100 EXAMPLE 2 The procedure of Example 1 was repeated using a water solution containing 500 ppm of 4-biphenyl methylcarbamate,

Results are given below in Table II.

TABLE ll Kill after 3 days 500 ppm 4-biphenyl methylcarbamate 100 EXAMPLE 3 The procedure of Example 1 is repeated using the compounds listed in Table III below. Results are substantially similar to those of Example 1.

Table III EXAMPLE 4 A post-emergent test is conducted by spraying 4- aminobiphenyl as an aqueous solution on soil around nematode-infested plants at a dosage of pounds per acre. Soil samples are taken 12 months afler treatment and examined as follows: Approximately 200 grams of soil are screened to remove roots and stems. This screened sample is extracted by the standard Baermann funnel technique for 24 hours. At the end of this period, 50 cc. of liquid is withdrawn and agitated. A 5 cc. portion of the extracted liquid is transferred to a Syracuse watch glass which had been marked off into 8 sections for counting purposes. Nematodes present in the samples are counted. The number of nematodes in the samples of treated soil are substantially less than in samples of untreated soil. Also, the appearance of the plants in the treated soil is superior to the appearance of the plants in the untreated soil.

We claim:

1. A process for controlling nematodes which comprises applying to said nematodes a nematocidal effective amount of 4- aminobiphenyl. 

